[Feature Request] OPF Metadata Update Mode for EPUB files

[LazyGeniusMan]

Light Novel support has been added since v0.19.0 and stabilized in v0.20.0, but currently it's only target API to update the metadata. One of file format usually used for light novel is EPUB, which store metadata in OPF file inside the EPUB archive.

It would be nice if it's also possible to write metadata into the OPF file directly similar to how we can write metadata into ComicInfo file in CBZ files.

Something to keep in mind is that EPUB 2 and EPUB 3 have a bit different way to store certain metadata¹.

Footnotes

1. https://wiki.kavitareader.com/en/guides/managing-your-files/ebooks ↩

[LazyGeniusMan]

This has been discussed on discord but I'll also write it in this issue.

So far the OPF mode seems working fine with some notes:

1. Eventhough orderBooks is set to true, currently it's not being used to set series index in OPF mode.
2. OPF mode option in komf-userscript has not been added.